Many knee problems are a result of the aging process and continual wear and stress on the knee joint (i.e., arthritis). Other knee problems are a result of an injury or a sudden movement that strains the knee. Common knee problems include the following: sprained or strained knee ligaments and/or muscles, torn cartilage, tendonitis, and arthritis.

A brain tumor is an abnormal growth of tissue in the brain. The tumor can either originate in the brain itself, or come from another part of the body and travel to the brain (metastasize). Brain tumors may be classified as either benign (non-cancerous) or malignant (cancerous), depending on their behavior

The most common type of breast infection is lactational mastitis. With this condition, which occurs when a woman is breastfeeding, the nipples become cracked and sore, allowing bacteria from the baby’s mouth to enter the ducts and rapidly multiply in the milk. Occasionally, infection also arises from a blocked milk duct. In both cases, the breast becomes hard, reddened, hot, and painful. Nonlactational mastitis is similar to lactational mastitis but occurs in nonlactating women.